RIBBON TAKE-UP DEVICE IN PRINTER FOR RECIPROCAL PRINTING

PURPOSE:To enable a smaller ribbon take-up device, by supporting a movable gear with a play not less than that required for engagement with two systems of wheel trains so that the movable gear is moved to be engaged with one of the wheel trains when a carriage is moved. CONSTITUTION:When the carriage is moved in the direction of arrow A, the movable gear 12 is engaged with a rack 11, and the resistance maintains the gear 12 in a stopped state until a rotary shaft 12a comes to the left end of a slot 14, on which the gear 12 is moved in the direction of the arrow A in the manner of being pushed out at the left end part of the slot 14. The gear 12 transmits counterclockwise rotation to a gear 15, thereby rotating a driving gear 18 counterclockwise, and the rotation is transmitted to a take-up shaft 19 to take up a thermal ribbon. On the other hand, when the carriage is moved in the direction of arrow, the gear 12 remains stationary until the shaft 12a comes to the right end of the slot 14, on which the gear 12 is engaged with a gear 16, and clockwise rotation of the gear 12 causes the driving gear 18 to rotate counterclockwise, thereby taking up the ribbon is a fixed direction.